diff --git a/code/Makefile b/code/Makefile
index c0114d1f4..89ba53382 100644
--- a/code/Makefile
+++ b/code/Makefile
@@ -38,13 +38,13 @@ SHELL = /bin/sh
 # STANDARD_CHECK = checking for Fortran 2008, compiler dependend
 ########################################################################################
 
-#auto values will be set by setup_code.py
-FFTWROOT   := auto
-IMKLROOT   := auto
-ACMLROOT   := auto
-LAPACKROOT := auto
-
+#any values will be overwritten by setup_code.py
+FFTWROOT   ?= auto
+IMKLROOT   ?= auto
+ACMLROOT   ?= auto
+LAPACKROOT ?= auto
 
+# if F90 empty: ifort if present, otherwise gfortran
 ifeq ($(wildcard ifort),)
 F90?=gfortran
 else
diff --git a/code/setup/setup_code.py b/code/setup/setup_code.py
index 33b3ab850..4112bbb04 100755
--- a/code/setup/setup_code.py
+++ b/code/setup/setup_code.py
@@ -76,13 +76,13 @@ content = makefile.readlines()
 makefile.close()
 makefile = open(os.path.join(baseDir,'Makefile'),'w')
 for line in content:
-  m = re.match(r'(FFTW|IMKL|ACML|LAPACK)ROOT\s*:?=',line)
+  m = re.match(r'(FFTW|IMKL|ACML|LAPACK)ROOT\s*\?=',line)
   if m:
     if m.group(1).lower() in damaskEnv.pathInfo:
       substitution = damaskEnv.pathInfo[m.group(1).lower()]
     else:
       substitution = ''
-    line = '%sROOT := %s\n'%(m.group(1),substitution)
+    line = '%sROOT ?= %s\n'%(m.group(1),substitution)
   makefile.write(line)
 makefile.close()
 
diff --git a/processing/setup/setup_processing.py b/processing/setup/setup_processing.py
index 519677909..f2291c73a 100755
--- a/processing/setup/setup_processing.py
+++ b/processing/setup/setup_processing.py
@@ -2,7 +2,7 @@
 
 # Makes postprocessing routines acessible from everywhere.
 
-import os,sys,glob,string
+import os,sys,glob,string,subprocess
 from damask import Environment
 from optparse import OptionParser, Option
 
@@ -41,8 +41,9 @@ compilers = ['intel','ifort','intel32','gfortran','gnu95']
 
 parser.add_option('--F90', '--f90',     dest='compiler', type='string', \
                                         help='name of F90 compiler')
-                                        
-parser.set_defaults(compiler  = 'ifort')  
+parser.set_defaults(compiler  = {True:'ifort',False:'gfortran'}[\
+                                 subprocess.call(['which', 'ifort'],\
+                                 stdout=subprocess.PIPE, stderr=subprocess.PIPE) == 0])
 (options,filenames) = parser.parse_args()
 
 if options.compiler not in compilers: